Valveless two-cycle motor



. 1927' F. BALCERZAK VALVELESS TWO-CYCLE MOTOR Filed May 29. 1922 Flag;

I I, 7 INVLNTOR.

BY W flaw V ATTORNEYS.

Patented Aug. 16, 1927. I I UNlTED STATES PATENT OFFICE. I

, FRANK mtonnznx or MILWAUKEE, wxsoonsm.

VALVELESS TWO-CYCLE MOTOR.

Application filed Kay 29, 1922. I Serial No. 584,825.

engine which is of very simple esign and of sturdy construction.

Further objects of this invention are to rovide a two-cycle engine utilizing a diferential piston action in which the pistons may be readily machined without necessitating the use of special tools; in which the differential cylinder and main cylinder may 'also be similarly machined in the usual.

manner without using special equipment; and to provide a novel and eflicient mterlocking construction of certain of the parts of the engine, thereby avoiding a needless complication of threaded parts or bolts and screws.

. Embodiments of the invention are shown in the accompanying drawings, in which:

Fig. 1 is an elevation partly in section of a two-cycle engine.

Fig. 2 is a section on the line 22 of Fi 1.

The engine comprises a crank case 1 upon which is secured a cylinder indicated at 2 in any of the usual or conventional ways, such, for example, as by machine screws or bolts, not shown. This cylinder comprises a main or inner portion 3 which is separated from an outer portion 4 to form a water jacket as indicated at 5. A top 6, constructed in a similar manner, may be bolted upon the upper.end of the cylinder, thereby providing free access to such innerportion during themachining operations. Th1s cylinder hasits outer or jacketing port on 4 contracted adjacent its lower endas indicated at 5 and, at such portion, is provided with an outwardly projecting flange 6.

The crank-case 1 may be a hollqw casing, as indicated in the drawing, provided with the usual bearings or journals 7 within. which the crank shaft 8 is mounted.

The upper portion of the crank case has a' flat machined surface 9' upon which the machined bottom portion of the flange 6 rests.

A smaller or auxiliary 10 is forme in thecontracted; portion of the cylinder and is provided with an outwardly cylinder or sleeve positioned within a circular opening extending flange 11. This flangeis gripped between a shoulder portion of the contracted portion 5 of the cylinder andflthe upper machined surface of the crank case, thereby securely holding and positioning the sleeve 10. This sleeve 10 is provided with a bored interior 12 and a machined exterior 13, the latter being of relatively small extent. Its outer surface may be tapered or conical, as

shown in the drawing, to thereby lessen the weight of such member.

The iston employed in this engine is of the di erential type having a relatively large or cylindrical portion and a relatively small or second cylindrical portion. The larger portion has an end 14; from which the usual sleeve 15 depends. This piston may be provided with an upper set of piston rings 16 and with one or more lower rings 17. It has .an upwardly projecting deflector 18 for guiding the incoming fresh charge upwardly. From the under side of the cylindrical portion 14 and integrally connected therewith, a shank or contracted portion 19 extends downwardly. This portion, as indicated 'in the cross sectional View shown in Fig. 2, is of star-shaped formation, thereby securing both lightness and strength. This portion 19 gradually merges into and is integrally connected withthe second cylindrical portion or smaller cross-head piston 20 which may be provided with cross-head piston rings 21. The second cylindrical portion or crosshead piston 20 has an interior hollow portion within which the connecting'rod 21 is 'pivotally mounted in any usual or convenper pis on terminates in planes coinciding with t e plane of the upper portion of the lowe piston 20 or else spaced therefrom so that the sleeve 15 of the upper piston does inner cylinder wall and that the transfer duct ope'ns'at a point slightly below the upper'cdge of the exhaust, openings 23. The transfer openings 2 Lv are provided upon the opposite side of the cylinder and adjacent, and shielded by, the deflector 18. These transfer openings communicate with the transfer passage 25 which in turn communicates with the space 26 formed between the upper piston sleeve 15 and the shell or auxiliary cylinder 12. This space. it is to be noted, communicates with the space 27 'inside of the auxiliary cylinder as such auxiliary cylinder terminates a distance below the bottom edge of the upper portion 14: of the main piston. The inlet duct 28 is provided with a port 29 which is closed by the sleeve 15 of the main piston when the parts are in the position shown in Fig. 1.

The operation of the engine is as follows: When the diflerential piston moves upwardly, it will be seen that a partial vacuum is created in the space below the main piston as the displacement of the main piston is greater than that of the auxiliary or lower piston. When the lower edge of the sleeve passes the port 29 of the inlet opening, the fresh charge rushes into the above noted space. Upon a downward stroke of the piston, this fresh charge is compressed due to the difference in'displacement of the two pistons. When the pistons have almost completed their downward stroke, the ports 24 of the transfer duct are uncovered and the fresh compressed charge rushes into the upper portion of the cylinder and is deflected by the member 18. Upon the upper stroke of the piston, this fresh charge is iighly compressed and at a suitable instant is ignited by. means of the spark plug 30.

-The resulting explosion forces the differential piston downwardly. As the piston nears the lower limit of its stroke, it first uncovers the exhaust ports 23 as the upper edge of such ports is located above the upper edge of the ports 24. The exhaust gases, therefore, are discharged through the exhaust duct 22, the incoming fresh charge entering the apertures upon the opposite side of the cylinder and, after being deflected upwardly by the member 18, washing the major portion of the remaining burntgases outwardly through the exhaust ports. I

It will be seen that a two-cycle internal combustion engine has been provided in which crank case compression is avoided and that this engine is composed only of simple and readily produced parts. It is to be particularly noted that the construction of the engine is such that all of the surfaces which must be machined may be readily reached by any of the usual tools employed in the production of internal combustion engines.

I claim:

7 In a two-cycle internal combustion engine having a cylinder and a sleeve within said cylinder in axial alignment therewith and of less diameter than said cylinder, a piston comprising a cylindrical portion adapted to fit said engine cylinder, a second cylindrical portion adapted to fit within said sleeve and being of less diameter than the first mentioned portion co-axial therewith and wholly longitudinally exterior to the first mentioned portion, and a shank portion connecting said cylindrical portions and bemg of less diameter than the second cylindrlcal portion, said cylindrical portions and shank being integrally connected,

whereby to obviate machining of any portion of said piston within the first mentioned cylindrical portion.

FRANK BALCERZAK. 

